The investigation in progress was designed to study the sympathetically-mediated effects of various pharmacologic agents on the peripheral vasculature and heart in experimental cardiogenic shock and, in turn, the role of these effects on myocardial oxygen balance and modification of reversibly ischemic damage resulting from coronary occlusion. Whether ventricular pump function can be significantly improved and infarct size reduced by pharmacologic means is being determined. The state of left ventricular performance is being evaluated by its velocity of contraction, rate of power generation, minute work, and compliance or relaxation ability. The four pharmacologic agents selected for evaluation this study are the glucocorticoid, methylprednisolone sodium succinate, the vasodilator sodium nitroprusside, and the alpha and beta adrenergic agonists, dopamine HC1 and 1-norepinephrine. To what degree these therapeutic agents alter cardiac work, cornary blood flow, myocardial oxygen consumption, energy balance, and the extent of reversibly ischemic damage in relation to their cardiac and peripheral vascular effects is being investigated. Additionally, whether an elevation in the chronotropic or inotropic state of the heart or an increase in ventricular preload or afterload is more expensive in terms of cardiac work and oxygen consumption or which combination of hemodynamic effects is more favorable in protecting jeopardized ischemic myocardium from irreversible necrosis will be assessed. Completion of the following study will hopefully provide a more concrete basis of therapeutic combination of agents for the cardiogenic-shocked patient. BIBLIOGRAPHIC REFERENCE: Niazi, Z., Beckman, C., Shatney, C., and Lillehei, R.C.: Use of Monitoring to improve survival in shock. Geriatrics, July, 93-103, 1975.